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Is signal repeater harmful to people?

Nowadays, 5G mobile phone is becoming more and more popular and almost everyone has one. The main function of a mobile phone is to make a call, and the most important thing is stable signal strength while making a call. WiFi wireless network signal, which is amplification of mobile phone signal function, is covering in many places such as public places, and private home. I think there should be a lot of people who know about mobile signal repeater, but I don't know how many of them know its working principle. People always worry that the radiation of electronic equipment will do harm to human body This article is to tell you the basic characteristics of mobile signal repeater and to solve the question: is a mobile signal repeater harmful to human body? ATNJ Mobile Signal Repeater.pdf The electromagnetic signal strength from a mobile signal repeater is very weak. As long as the mobile signal repeater is qualified and produced by regular manufacturers, and its electromagnetic radiation intensity is tested by the national authoritative testing organization like National Institute of Environmental Health China CDC, all samples of electromagnetic signal strength tested is lower than the limited value in GB8702-88 of “Regulations for electromagnetic radiation protection” stipulated by State of Environmental Protection Agency (This standard in DB8702-88 is only 1 / 5 of the European standard), it won’t do any harm to human body. Therefore, there is no need to panic. The power of a mobile signal repeater is very small (≤ 1W), and its working range is around 20-meter to 30-meter diameter, which will not cause any interference to the base station. In addition, mobile signal repeater is only used in some specific occasions, and its impossible to endanger public information security. The frequency of electromagnetic signals sent from a mobile signal repeater is completely in the working frequency band of mobile phones stipulated by our country. The signals are always in a relatively static and constant state, and will not affect any other electronic equipment, interfere with human brain, nor affect human normal thinking.

2021

03/28

What is self excitation?

Self excitation means that the signal amplified by the repeater enters the receiver again for secondary amplification, resulting in the power amplifier working in saturation state. Self excitation only appears in the radio repeater. Because the fiber repeater is directly coupled with the base station signal, the fiber repeater will not generate self excitation. If the optical fiber repeater is unable to make a call with signal or the call quality is poor, it is recommended to check the uplink and downlink attenuation and repeater hardware equipment.   The gain and isolation change of signal repeater caused by the temperature change or base station parameter change would make the input signal to signal repeater higher, which causes self excitation. When debugging the repeater, it is necessary to keep room for not too much pursuit of amplification function of repeater and too large gain. For the repeater with fault record, it is difficult to detect the self excitation in reverse channel of repeater. Because the forward channel of the repeater always has a base station signal input, if the repeater is self-excited, the forward amplifier may be overloaded. After some models of repeaters detect that the amplifier is overloaded three times, they immediately shut down the repeater and give a clear fault record, which is easy to find. The input signal of the reverse channel amplifier changes greatly, and the mobile phone transmitter is not always in the transmitting state and the distance is far some times and near some times. In some cases, the reverse channel amplifier will self excite, but the amplifier will return to normal due to the sudden disappearance of the input. Reverse channel amplifier self-excited time is short, only a few seconds, and irregular, sometimes several hours are not self-excited once, very difficult to remove the fault. In the area where the repeater is installed, if the mobile phone communicates with the local telephone, the mobile phone could hear clearly, but the local telephone cant, and the sound quality is extremely poor, which may be caused by the self excitation of the reverse channel amplifier of the repeater.   ATNJ Mobile Signal Repeater.pdf When the repeater is not installed properly, the isolation of the receiving and transmitting antenna is not enough, and the gain of the device is too large, the output signal is fed back to the input after delay, resulting in serious distortion of the output signal of the repeater and self excitation. After self excitation, the quality of signal spectrum waveform becomes poor, which seriously affects the quality of the call and causes the phenomenon of dropping the call.   There are two ways to solve the self excitation phenomenon, one is to increase the isolation between the donor and the re-transmission antenna, the other is to reduce the gain of the repeater. When the coverage of repeater is small, the gain can be reduced. When the coverage of repeater is large, the isolation should be increased.   The following methods are mainly used in the project: - increase the horizontal and vertical distance of the transmitting and receiving antenna - increase the shelter, such as installing the shielding net, etc. - increase the directionality of the donor antenna, such as using the parabolic antenna - select the re-transmission antenna with stronger direction, such as the directional angle antenna - adjust the angle and direction of the donor and the re-transmission antenna, so as to make them as backward as possible.

2021

09/21

Why are mobile phone signal amplifiers widely used?

We can often see that mobile phone signal amplifiers are installed in many places such as tall buildings, basements, shopping malls, restaurants, karaoke sauna massage and other entertainment places, underground civil air defense projects, subway stations and so on, so as to solve the problem of signal difference in these signal blind areas and weak areas. Why are mobile phone signal amplifiers widely used by users? There are five main reasons.   ATNJ Mobile Signal Repeater.pdf 1. With the rapid development of the mobile communication industry, mobile communication users are also increasing, resulting in smaller and smaller cellular planning, lower and lower base station location and smaller signal coverage.   2. With the development of urban construction, high-rise buildings continue to emerge. Based on the shadow effect of wireless transmission, the signal blind area of mobile communication will be formed behind or in the middle layer of these high-rise buildings. 3. During the construction of cellular mobile communication base station, because the interference of adjacent cells should be avoided, the main lobe of the antenna radiation field pattern has a large downward inclination, so that the middle and upper parts of high-rise buildings generally can not receive signals effectively. 4. Due to the shielding effect of buildings on electromagnetic waves, some closed large amplifier systems such as tunnels, subways, underground shopping malls, entertainment cities, parking lots, hotels and office buildings can be used well in the whole range of mobile phone signals, which brings great convenience to the staff or guests inside. 5. The construction of base stations in some remote areas is not in place, and users need operators to build additional base stations. However, the signal coverage project is recommended to have a long period and cost a lot, so most users prefer to install mobile phone signal amplifiers for signal coverage.

2022

03/11

Is the Signal Repeater useful?

As we all know, mobile phone signals establish communication relations through the transmission, transmission and reception of electromagnetic waves. However, with the increasing construction and development of the city, there are many high-rise buildings, which will block the signals. On the back of some tall buildings, shopping malls, restaurants, entertainment places and subway stations in the basement, Because the signal is blocked, you can't use your mobile phone to surf the Internet or make calls, which causes a lot of trouble, but the mobile phone signal amplifier can be easily solved. If we only need to install the mobile phone signal amplifier system in the place where the signal is not strong, then the mobile phones within this range can quickly receive the signal, so that the mobile phone can be used normally. This method can bring great convenience and benefits to the people working in these places and those who come here for consumption. Although the mobile phone signal amplifier brings people a lot of convenience, because there are many kinds of mobile phone signal amplifiers and have their own characteristics, the requirements for mobile communication network and signal absorption capacity are different. Moreover, due to different geographical environment and occasions, the solutions adopted are also different. When setting the signal amplifier, we should also make objective analysis and treat it differently. Compared with the wireless repeater, the problem of signal isolation is also very key. When we use the mobile phone signal amplifier to receive the signal, we should strive for the purity of the signal it obtains. Otherwise, if the base station is dense, it will be more difficult to obtain the signal. In this way, the mobile phone signal amplifier will also interfere with the base station, and the signals in this area will be affected as soon as they are combined, which is not worth the loss.   In many countries and regions in the world, the imperfect construction of base stations leads to the problem of poor home signal. Therefore, it is a good choice to select the signal repeater to cover the signal blind area. Shenzhen ATNJ Communication Technology Co., Ltd is a leading signal repeater manufacturer in China, committing to the R&D and production of signal repeater with over 10 years experience. Choosing ATNJ signal repeater, we would provide good-quality product and good service. ATNJ Mobile Signal Repeater.pdf

2022

04/13

Villa Mobile Phone Signal Enhancement - Why is the mobile phone signal so poor in the villa area?

   Why is the mobile phone signal in the villa area so poor and cannot receive the signal? The villa mobile phone signal enhancement helps you solve the problem of poor signal. The editor summarizes the following three reasons for the poor mobile phone signal in villas: 1. The signal of the villa itself is poor, far away from the signal tower, and the mobile phone cannot receive the signal in the weak signal area. 2. The thick wall structure of the villa area causes signal blockage. 3. Bad signal due to interference.     Since the mobile phone receives signals to work through the propagation of electromagnetic waves, the base station establishes a connection between the transmitted radio waves and the mobile phone, so as to achieve the purpose of voice call. Therefore, the interference of electromagnetic waves can have a negative effect on mobile phones.    It is normal for the mobile phone to display a 4G signal and change to a 3G or 2G signal when making a call! It is not caused by a malfunction of the mobile phone or a malfunction of the base station. Here's an explanation of why this happens: 1. 4G has only one data channel (commonly known as Internet channel), while 2G and 3G have two channels, data channel and voice channel. So both 2G and 3G can access the Internet and make calls, while 4G can only access the Internet because it only has a data channel. 2. In the early days of 4G, in order to meet the needs of mobile phones when they can make calls when using 4G networks, a solution called CSFB (circuit domain fall) has been developed, which is that when the mobile phone uses the 4G network to make calls or receive calls, the network will automatically fall back from the 4G network to the 2G or 3G network and then start to make and receive calls. However, this technology has a disadvantage, that is, it cannot be connected to the Internet when making calls, so it is inconvenient for some users with more business. 3. Now that 4G technology has matured, in order to meet the better experience of mobile phone users, VoLTE (high-definition voice call) technology has been developed to use 4G network to make calls and access the Internet at the same time. Mobile phones use the data channel of the 4G network to make calls and surf the Internet, and the call quality is clearer than that of 2G and 3G calls. 4. Disconnection due to cross-zone handover failure. Network operators serve users by transmitting wireless signals from base stations, and the range of base stations is limited, so there may be many base stations in an area. All the base stations are combined into a network system, each base station has its own range, beyond this range, the mobile phone has to replace the base station, so as to keep the mobile phone always in the network.     If you want a good signal, you can choose to use a mobile phone on high ground, but it is not convenient. At present, the hot-selling villa mobile phone signal enhancement of Shenzhen ATNJ Communication Technology Co.,LTD. is very suitable for users in some residential areas, basements, villas, urban villages, elevators, sewage plants, etc. Villa cell phone boost can amplify the cell phone signal in our room, thus improving the quality of the network.      Better signal,better life---cell phone booster,cell phone signal booster,cell signal booster,network booster,4g repeater,cell phone signal booster for rural areas,4g mobile signal booster

2023

12/27

The most important thing is to find the signal source during installation---mobile phone signal amplifier

  The era we are in is the era of modern information technology. The popularization of the Internet and mobile phones has brought us infinite convenience in our daily life. Nowadays, everyone has mobile phones, especially in today’s smart phones. Come, most of the time of our day together is accompanied by a mobile phone. The mobile phone is important, but the mobile phone signal is more important, because it will not only affect the quality of our calls, but also directly affect our network, which will cause the mobile phone to be unable to access the Internet, which will bring us both in life and work. A lot of inconvenience and trouble, so how do we solve it?     When installing and using a mobile phone signal amplifier, the mobile phone signal source is extremely important. The mobile phone signal source is the soul of the mobile phone signal amplifier. If there is no signal source, the installation and use of the mobile phone signal amplifier will also be ineffective. In order to give full play to the signal enhancement machine and equipment , we must choose a good signal source.      The signal source refers to the location where there is a data signal, and the signal source is divided into strength and quality. The higher the signal strength, the better the actual effect of the installed and used mobile phone signal amplifier.   ATNJ Mobile Signal Repeater.pdf   Many people install the mobile phone signal amplifier of Shenzhen Antonage Communication Technology Co., Ltd. and think that if the signal amplifier is bought and installed, there will be a data signal. In fact, this is not the case. It is based on the reading of the Yagi antenna, and then According to the transmission of the radio frequency cable to the mobile phone signal amplifier, after the enhancement, we can receive a good data signal.     In view of the fact that everyone's mobile phones rely on radio waves to spread and create communication data signals, and due to the isolation of mountains or buildings, in some poor areas and their large buildings, mobile phone signals cannot reach smoothly, so everyone cannot use mobile phones. Therefore, the mobile phone signal amplifier can effectively solve those problems. Therefore, it is necessary to find a good signal source in the process of installing and using the mobile phone signal amplifier. The quality of the signal source will always affect the actual effect of installing and using the mobile phone signal amplifier.

2022

09/20

What are the precautions for installing a signal amplifier

  The mobile phone signal amplifier is specially designed to improve the problem of weak signal and no signal. The whole set of signal amplifier is mainly composed of signal amplifier host, receiving antenna and transmitting antenna. A host with a signal amplifier is also the most convenient and effective way to improve mobile phone signals.        Mobile phone signal amplifier (professional name: repeater) consists of antenna, radio frequency duplexer, low noise amplifier, mixer, ESC attenuator, filter, power amplifier and other components or modules to form up and down amplification links. The basic principle of its work is: use the forward antenna (donor antenna) to receive the downlink signal of the base station into the repeater, amplify the useful signal through the low-noise amplifier, suppress the noise signal in the signal, and improve the signal-to-noise ratio (S/N ratio). ); then down-converted to the intermediate frequency signal, filtered by the filter, amplified at the intermediate frequency, and then up-converted to the radio frequency by frequency shifting, amplified by the power amplifier, and transmitted to the mobile station by the backward antenna (retransmission antenna); at the same time, the backward antenna is used. The uplink signal of the mobile station is received, and is processed by the uplink amplification link along the opposite path: that is, it is transmitted to the base station through a low noise amplifier, a downconverter, a filter, an intermediate amplifier, an upconverter, and a power amplifier. So as to achieve two-way communication between the base station and the mobile station. ATNJ Mobile Signal Repeater.pdf What are the precautions for installing a mobile phone signal amplifier?   1. When purchasing, pay attention. Generally, there are two kinds of large Yagi antennas and small antennas on the market. The larger antenna has a larger gain, but at the same time, the radiation is also relatively large, which is suitable for the improvement of mobile phone signals in factories and other places. It is generally recommended to use a small suction cup antenna at home, and the radiation is relatively small.     2. Do not install the indoor antenna and the outdoor antenna inversely. The principle of the machine is to transfer the outdoor signal to the indoor for amplification, so the interface of the indoor Indoor and the outdoor outdoor cannot be reversed, otherwise it will have no effect.       3. The distance between the host and the outdoor antenna should be as far away as possible, preferably more than 5 meters. If the distance is too close, the outdoor antenna will receive the indoor amplified signal, and after amplification, it will cause "self-excitation". It has to be as far as possible, or at least there is a wall between them. If the effect is not good, try to move the distance further.

2022

09/20

What is a power amplifier? Explain the types, categories and applications of power amplifiers in detail

What is a power amplifier?   ATNJ Mobile Signal Repeater.pdf A power amplifier is an electronic amplifier designed to increase the power amplitude of a given input signal. The power of the input signal is increased to a level sufficient to drive the load of output devices such as speakers, headphones, RF transmitters, etc. Unlike voltage/current amplifiers, power amplifiers are designed to drive the load directly and serve as the final module in the amplification chain. The input signal to the power amplifier must be above a certain threshold. So instead of passing the raw audio/RF signal directly to the power amplifier, it is first pre-amplified with a current/voltage amplifier and sent to the power amplifier as an input after necessary modifications. Below you can observe the block diagram of the audio amplifier and the usage of the power amplifier. In this case, the microphone is used as the input source. The signal strength from the microphone is not strong enough for the power amplifier. So first preamp it and then slightly increase its voltage and current. The signal then passes through tone and volume control circuits, which make aesthetic adjustments to the audio waveform. Ultimately, the signal passes through a power amplifier whose output is fed to the speakers. Types of Power Amplifiers Depending on the type of output device connected, power amplifiers are divided into the following three types: audio power amplifier RF Power Amplifier DC power amplifier audio power amplifier This type of power amplifier is used to increase the power level of weaker audio signals. Amplifiers used in speaker drive circuits for TVs, mobile phones, etc. fall into this category. Audio power amplifiers have outputs ranging from a few milliwatts (like headphone amplifiers) to several kilowatts (like power amplifiers in Hi-Fi/home theater systems). RF Power Amplifier Wireless transmission requires modulated waves to be sent over long distances through the air. The antenna is used to transmit the signal, and the transmission range depends on the power of the signal fed to the antenna. For wireless transmissions such as FM radio, antennas require input signals with powers of thousands of kilowatts. Here, an RF power amplifier is used to increase the power amplitude of the modulated wave to a level sufficient to achieve the desired transmission distance. DC power amplifier A DC power amplifier is used to amplify the power of a PWM (pulse width modulation) signal. They are used in electronic control systems that require high power signals to drive motors or actuators. They take input from a microcontroller system, increase its power, and feed the amplified signal to a DC motor or actuator. Power amplifier class There are several ways to design a power amplifier circuit. The operation and output characteristics of each circuit configuration are different from each other. To differentiate the characteristics and performance of different power amplifier circuits, power amplifier classes are used, in which letter symbols are assigned to identify the method of operation. They are roughly divided into two categories. Power amplifiers designed to amplify analog signals are class A, B, AB or C. Power amplifiers designed to amplify pulse-width modulated (PWM) digital signals are located under D, E, F, etc. The most commonly used power amplifiers are those used in audio amplifier circuits, and they are class A, B, AB or C. So let's look at them in detail. Class A Power Amplifier An analog waveform consists of positive highs and negative lows. In this type of amplifier, the entire input waveform is used in the amplification process. A single transistor is used to amplify the positive and negative halves of the waveform. This makes their design simple and makes Class A amplifiers the most commonly used type of power amplifier. Although such power amplifiers have been replaced by better designs, they are still popular among hobbyists. In this type of amplifier, the active elements (electronic components used for amplification, in this case transistors) are always in use, even when there is no input signal. This generates a lot of heat and reduces the efficiency of the Class A amplifier to 25% in the normal configuration and 50% in the transformer coupled configuration. The conduction angle of a Class A amplifier (the portion of the waveform used for amplification in 360 degrees) is 360°. Therefore, the signal distortion level is very small, which can provide better high frequency performance. Class B power amplifier Class B power amplifiers are designed to reduce the efficiency and heating issues present in class A amplifiers. Such amplifiers use two complementary transistors instead of a single transistor to amplify the entire waveform. One transistor amplifies the positive half of the waveform and the other transistor amplifies the negative half of the waveform. Therefore, each active device turns on half (180°) of the waveform, two of which when on will amplify the entire signal. Due to the two-transistor design, the efficiency of class B amplifiers is greatly improved compared to class A amplifiers. They can achieve around 75% of the theoretical efficiency. Such power amplifiers are used in battery powered devices such as FM radios and transistor radios. Since the two halves of the waveform overlap, there is very little distortion in the intersection area. To reduce this signal distortion, class AB amplifiers are designed. Class AB power amplifier A Class AB amplifier is a combination of Class A and Class B amplifiers. These amplifiers are designed to reduce the problems of inefficient class A amplifiers and signal distortion in the crossover area of ​​class B amplifiers. It can maintain high frequency response like a class A amplifier and maintain good efficiency like a class B amplifier. A combination of diodes and resistors is used to provide a small bias voltage, thereby reducing waveform distortion near the crossover region. Therefore, the efficiency drops slightly (60%). Class C power amplifier Class C power amplifiers are designed to achieve higher efficiency at the cost of reduced linearity/conduction angle (below 90°). In other words, the quality of amplification is sacrificed for efficiency. A smaller conduction angle means more distortion, so this type of amplifier is not suitable for audio amplification. They are used for high frequency oscillators and amplification of radio frequency signals. Class C amplifiers typically contain a tuned load that filters and amplifies the input signal at certain frequencies, while suppressing waveforms at other frequencies. In this type of power amplifier, the active elements are turned on only when the input voltage is above a certain threshold, reducing power consumption and increasing efficiency. Other power amplifier classes Power amplifiers D, E, F, G, etc. are used to amplify PWM modulated digital signals. They fall into the category of switching power amplifiers that turn the output on or off continuously without any other level in between. Due to this simplicity, power amplifiers belonging to the above categories can achieve theoretical efficiencies as high as (90-100)%. Application field The following are the applications of power amplifiers in different fields: Consumer Electronics: Audio power amplifiers are used in virtually all consumer electronics devices, from microwave ovens, headphone drivers, televisions, mobile phones and home theater systems to theater and concert enhancement systems. Industrial: Switching power amplifiers are used to control most industrial actuator systems such as servos and DC motors. Wireless Communications: High power amplifiers are important for transmitting cellular or FM broadcast signals to users. Thanks to the power amplifier, higher power levels are possible, thereby increasing the data transfer rate and availability. They are also used in satellite communication equipment. in conclusion A quick introduction to the concept of a power amplifier. You know what a power amplifier is and its requirements, the different types and classes of power amplifiers, and several applications.

2022

09/02

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